1. Field of the Invention
The present invention generally relates to coupling circuits, and more particularly, to a broad band directional coupling circuit which permits detection of signals propagating simultaneously in opposite directions on a single-signal path or transmission line.
2. Description of the Prior Art
Various types of directional couplers are known in the art and are typically used for splitting or mixing signals on transmission lines or the like. Most directional couplers, however, are narrow or limited-band devices since the coupling network generally employs reactive devices. The use of reactive devices in the coupling network necessarily limits the frequency band of operation of the directional coupler and often unduly complicates the design and construction of the coupler circuit.